The invention relates to a method of recording digital information signals on a removable rewritable disc like recording medium, with a program area of the disc and, prior to removal of the disc out of a recording apparatus, finalizing the disc with a lead-in and lead-out area comprising control information.
The invention further relates to an apparatus for recording digital information signals on/from a removable rewritable disc like recording medium, the apparatus comprising inputting means for receiving digital information signals, recording medium, receiving means for receiving the recording medium, recording means for reading the digital information signals on the recording medium, reading means for digital information signals stored on the recording medium, outputting means for outputting the read digital information signals, controlling means adapted to control recording digital information signals representing user data on a program area on the recording medium.
The PC world needs a replacement for the floppy drive. A rewritable storage medium of the disc like optical type, such as the CD-RW, seems to be a logical choice because the read function of the magnetic floppy is already replaced by the CD-ROM. All PC""s today are equipped with a CD-ROM and applications and software are distributed on CD-ROM. Therefore a recording medium like CD-RW or rewritable DVD, seems to be the perfect media to fill in the needed write capability. Recording media of the magneto-optical type already tried to fill this gap, but they all miss compatibility with the installed base. That is exactly what CD-RW for instance can deliver with the installed base of over approximately 200 million CDROM drives. CD-RW media are cheap and the capacity is sufficient for floppy use.
Furthermore, manufacturers of operating systems wants to get rid of legacy material like the floppy drive. For OEM companies the idea is attractive, as they can replace the floppy drive, the CD-ROM and the DVD-ROM drive by a one spindle drive like a Combi and by a double writer in the future. It will also add a new feature to the drive other then the ever-increasing speed
There are products on the market which enable to use a CD-RW like a floppy drive, but they don""t behave the way one would expect a CD floppy drive would do. The access time is too low, formatting time is too long and more important the drive does not fit into the strategy of current OS. The disc should be immediately available for dragging and dropping of files. A fast eject is required, deleting should be instant. Due to enable multiple drag and drop a defect management is required. However, the defect management should be done by the drive. This opens the way to use UDF 1.02 instead of UDF 1.5, which is not supported on the write side by manufacturers of Operating systems. Further background formatting must be done by the drive and not by the application or OS to minimize bus traffic, and interaction between the drive and the OS. Finally, Read/Modify/Write for packets should be done by the drive.
In consequence, amongst other things, it is an object of the invention to obviate the above-mentioned disadvantages. According to one of its aspects a method according to the invention is characterized by performing an initialization step comprising recording control data in a lead-in area which control data defines a general purpose area (GPA) within the program area of the disc and where after the disc is ready to record user data in a remaining data area of the program are.
Because of the very limited amount of data to be recorded, this step will be finished in just a few seconds. The disc is then ready for data storage. Further, the general purpose area can be used to add additional functionality by, for instance, storing device driver programs herein or allowing disc space to be used by said programs. As the general purpose area is still readable by legacy drives as this drives will report the start of the Lead-out area as the end of the user area, these drives may employ the added functionality. Thus compatibility is achieved.
An advantageous embodiment is obtained by adding defect management. In this case, the initialization-step comprises: defining a main defect table (MDT) in the lead-in area adapted to contain a list of address of defect areas and replacement areas; and defining a defect management area (DMA) within said general purpose area (GPA) adapted to contain replacement areas for defect-management. This is required in case of adding file drag and drop functionality equivalent to removable disc functionality.
A further advantageous embodiment is obtained by reserving space for device drivers to handle defect management. In this embodiment the initialization step comprises defining a general application area (GAA) within the general purpose area (GPA) adapted to contain application drivers adapted to handle defect management and/or support of specific operating systems. This enables legacy drives to handle the defect areas.
A further improvement is obtained by adding a sentinel area next to a defect table. In this case the initialization step comprises: defining a sentinel area (STL) within the lead-in area comprising dummy data adapted to be overwritten by a new main defect table when the main defect table (MDT) becomes defective. This sentinel area may be used advantageously for storage of proprietary information such as copy right information. This area may also be used to store a new defect table when the old table is wearing out.
drive is idle. In this case the initialization step is followed by a back-ground formatting step intended to be performed when no user data is being written to the disc, the back-ground formatting step comprising: a de-icing step comprising recording dummy data in blank areas within the data area, said de-icing step to be performed in the back-ground until the complete data area has been recorded with dummy data when not recorded already with user data. This has the advantage the medium is formatted before an eject request occurs.
The next embodiment performs a finalization step. The recording medium will be in a CD-ROM compatible state while the secondary defect table (SDT) is readable by a CD-ROM reader or legacy reader.
However, an advantageous embodiment is obtained by allowing an early-eject step. The eject time is made as short as possible while the recording medium leaves the drive in a CD-ROM or legacy drive compatible state. All data is recorded contiguously while the temporary defect table (TDT) may be used for defect management.
Other advantageous embodiments are disclosed in the description.